The high-performance Cisco 7500 Series Routers remain the market leader due to its breadth of advanced support for LAN/WAN services, redundancy, reliability, and performance.
A distributed architecture using Versatile Interface Processors (VIPs) is the key to the Cisco 7500's scalability. Each VIP has its own processor, which is capable of switching IP data packets and providing network services. This scenario allows the overall system performance of Cisco 7500 routers to scale up when they need to handle more high-speed network connections and more data packets. The RSP is still the master of the system. It runs routing protocols with other routers in the network to gather switching intelligence, which is then downloaded to the VIPs so that each can switch IP packets on its own.
In addition to performing packet switching, the VIPs can also provide a set of distributed IP network services, including access control, QoS, and traffic accounting (NetFlow). With the VIPs off-loading these IP switching and service functions from the RSP, the RSP can devote all its CPU cycles to handle other essential tasks. VIP distributed switching is the way to scale up system performance, and should be enabled where possible, to significantly reduce CPU utilization on the RSP.